This invention relates to a new carpet tile and method of making same and particularly to an improvement of a backing material for carpet tiles.
Carpet tiles are square, rectangular, rhombic, or assume even more complicated shapes, and each provides a plate-like carpet having an area of for example 0.03 to 2 m.sup.2. These carpet tiles are combined on a floor to provide a carpet without forming any clearance, and they are advantageous over ordinary types of carpets in that by merely fixing them onto a floor there can be formed a carpet easily and in that carpets of various impressions can be obtained by changing the combination of shape and color of carpet tiles. They are further advantageous in that when a portion thereof is stained or damaged the said portion alone can be replaced or repaired easily.
It is necessary that these carpet tiles when laid on a floor should adhere to the floor tightly enough to prevent them from partially coming off when a person walk thereon. As means for satisfying this requirement there is known the use of an adhesive or sticking agent or the use of needles or tacks. These methods, however, are disadvantageous in that their application is troublesome and the replacement of the carpet tiles laid on the floor by such methods takes more time and labor. As an improvement from such methods there is known the method in which a carpet tile itself is made heavier by the application of a backing material so that it has fixativity (laying stability). The said backing material is also intended to prevent the constituent threads of a carpet tile from coming off, to make the carpet tile stable dimensionally and to make it cushiony.
Thus, carpet tile backing materials must have a laying stability which allows the backed carpet tile to become stably fixed upon laying on a floor, in addition to the requirement that they must satisfy the requirements of backing materials for ordinary type carpets. And this laying stability must be imparted without using expensive materials.
Known heretofore as carpet backing materials are rubber latex type, elastomer type, synthetic resin type, and asphalt type, as is disclosed for example in Japanese Patent Publication Nos. 3839/1971, 20199/1973, 34556/1973, 17851/1977 and 4525/1978. However, the rubber latex type is disadvantageous in that, since its application must be followed by drying and vulcanization, there are required additional equipment and cost, and further in that the fibrous base material is damaged because during the said additional operation it is exposed to an elevated temperature for a long time. Heat melting types such as the elastomer type and the synthetic resin type have characteristics preferable to the rubber latex type, but are not desirable in point of cost performance. The asphalt type is less expensive, but the asphalt in ordinary use is insufficient in hardness and resistance to deformation under load, and when used as a backing material it can flow and move at ordinary temperature, resulting in the beauty of carpet tile being spoiled. Also from the standpoint of working environment the asphalt type is not desirable, because when heated in the backing operation it produces offensive odor and smoke.